Testing register form fails with password confirmation with Laravel 5

I'm trying to test my register form.

I wrote this test :

public function testUserRegistration()
{
    $response = $this->call('POST', 'auth/register', array(
        '_token' => csrf_token(),
        'name' => 'toni',
        'username' => 'toni@free.fr',
        'password' => 'toni19'
    ));

    // Error The given data failed to pass validation.

    $this->assertEquals(200, $response->getStatusCode());
}

When I run this test, it fails with following error :

Error The given data failed to pass validation.

And my controller code :

$this->validate($request, [
    'name' => 'required|unique:users',
    'username' => 'required|unique:users,username|email|min:3',
    'password' => 'required|confirmed|min:5'
], User::getFormMessages());

Thanks for your help.

via Chebli Mohamed